{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T21:09:55Z","timestamp":1792012195689,"version":"4.4.0"},"reference-count":37,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2025,2,9]],"date-time":"2025-02-09T00:00:00Z","timestamp":1739059200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2019s Horizon 2020 research and innovation program","award":["956720"],"award-info":[{"award-number":["956720"]}]},{"name":"European Union\u2019s Horizon 2020 research and innovation program","award":["UIDB\/04650\/2020"],"award-info":[{"award-number":["UIDB\/04650\/2020"]}]},{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["956720"],"award-info":[{"award-number":["956720"]}]},{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["UIDB\/04650\/2020"],"award-info":[{"award-number":["UIDB\/04650\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Objectives: To investigate the dynamics of accommodation during and immediately after a sustained reading task on a digital device across various age groups under monocular and binocular conditions. Methods: Seventeen subjects were selected and divided into three age groups: young adults (n = 4, age: 21.3 \u00b1 3.2 years), adults (n = 4, age: 34 \u00b1 3.56 years), and incipient presbyopes (n = 9, age: 45 \u00b1 3.61 years). Dynamic accommodation and disaccommodation were objectively measured using the WAM-5500 open-view autorefractor during 2 min of distance fixation (Maltese cross at 6 m), 5 min of sustained near reading on a teleprompter app at the nearest readable distance, and 2 min of distance vision. Six sequential temporal landmarks were identified. Quantitative metrics for accommodation lag (AL), slope of slow accommodation (SSA), slope of slow disaccommodation (SSD), peak velocity of accommodation (PVA) and peak velocity of disaccommodation (PVD) were obtained as absolute values of spherical equivalent refractive (SER) change. Results: SSA, SSD, and AL were significantly and positively correlated with age (\u03c1 = 0.75, 0.73, 0.51, respectively; p \u2264 0.038). For subjects under 45 years of age SSA and SSD increased quadratically with age, while for those above 45 years, both SSA and SSD decreased linearly. Linear regression of PVA and PVD with age indicated that the disaccommodation mechanism is faster than accommodation (slope = \u20130.15 and \u20130.23, respectively). PVA was significantly faster under monocular than binocular conditions (p = 0.124). Conclusions: Incipient presbyopes demonstrate a complex response in both accommodation and disaccommodation. The accommodation system responds quickly, but there is also a slower response that can provide up to an additional 1D of accommodative response during sustained near reading tasks. It is hypothesized that the crystalline lens exhibits hysteresis in returning to its unaccommodated state, due to its viscoelastic properties, which means it takes time to relax.<\/jats:p>","DOI":"10.3390\/jcm14041107","type":"journal-article","created":{"date-parts":[[2025,2,10]],"date-time":"2025-02-10T03:39:47Z","timestamp":1739158787000},"page":"1107","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Fast and Slow Response of the Accommodation System in Young and Incipient-Presbyope Adults During Sustained Reading Task"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9246-0455","authenticated-orcid":false,"given":"Ebrahim","family":"Safarian Baloujeh","sequence":"first","affiliation":[{"name":"Institute of Nanoscience and Materials of Arag\u00f3n (INMA), Spanish National Research Council (CSIC), 50009 Zaragoza, Spain"},{"name":"Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1045-4455","authenticated-orcid":false,"given":"Ant\u00f3nio","family":"Queir\u00f3s","sequence":"additional","affiliation":[{"name":"Clinical and Experimental Optometry Research Lab (CEORLab), Physics Centre of Minho and Porto Universities (CF-UM-UP), School of Sciences, University of Minho, 4710-057 Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rafael","family":"Navarro","sequence":"additional","affiliation":[{"name":"Institute of Nanoscience and Materials of Arag\u00f3n (INMA), Spanish National Research Council (CSIC), 50009 Zaragoza, Spain"},{"name":"Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9050-4170","authenticated-orcid":false,"given":"Jos\u00e9 Manuel","family":"Gonz\u00e1lez-M\u00e9ijome","sequence":"additional","affiliation":[{"name":"Clinical and Experimental Optometry Research Lab (CEORLab), Physics Centre of Minho and Porto Universities (CF-UM-UP), School of Sciences, University of Minho, 4710-057 Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Moore, M., Loughman, J., Butler, J.S., Ohlendorf, A., Wahl, S., and Flitcroft, D.I. (2021). Application of Big-Data for Epidemiological Studies of Refractive Error. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0250468"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"759","DOI":"10.1016\/0014-4835(92)90031-M","article-title":"Ageing and Changes in Protein Conformation in the Human Lens: A Raman Microspectroscopic Study","volume":"54","author":"Siebinga","year":"1992","journal-title":"Exp. Eye Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1492","DOI":"10.1016\/j.ophtha.2018.04.013","article-title":"Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia: Systematic Review, Meta-Analysis, and Modelling","volume":"125","author":"Fricke","year":"2018","journal-title":"Ophthalmology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1706","DOI":"10.1016\/j.ophtha.2015.04.014","article-title":"The Global Burden of Potential Productivity Loss from Uncorrected Presbyopia","volume":"122","author":"Frick","year":"2015","journal-title":"Ophthalmology"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Szostek, N., Buckhurst, H., Purslow, C., Drew, T., Collinson, A., and Buckhurst, P. (2018). Validation of Novel Metrics from the Accommodative Dynamic Profile. Vision, 2.","DOI":"10.3390\/vision2030034"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1016\/S0042-6989(00)00282-0","article-title":"Dynamics of the Accommodation Response to Abrupt Changes in Target Vergence as a Function of Age","volume":"41","author":"Heron","year":"2001","journal-title":"Vis. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"541","DOI":"10.18240\/ijo.2021.04.10","article-title":"Spasm of the near Reflex: A Common Diagnostic Dilemma?","volume":"14","author":"Papageorgiou","year":"2021","journal-title":"Int. J. Ophthalmol."},{"key":"ref_8","first-page":"168","article-title":"Spasm of accommodation","volume":"130","author":"Lindberg","year":"2014","journal-title":"Duodecim"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1007\/BF01960420","article-title":"Arbeiten aus dem Gebiete der Accommodationslehre VI: Die relative accommodation [reviewed by Atchison, D.A. Accommodation and presbyopia. Ophthalmic Physiol. Opt. 1995, 15, 255\u2013272]","volume":"52","author":"Hess","year":"1901","journal-title":"Graefes Arhiv. Ophthalmol."},{"key":"ref_10","first-page":"133","article-title":"\u201cDie\u201d Optische Abbildung in Heterogenen Medien Und Die Dioptrik Der Kristallinse Des Menschen [Reviewed by Eskridge, J. B. (1984). Review of Ciliary Muscle Effort in Presbyopia]","volume":"61","author":"Gullstrand","year":"1984","journal-title":"Am. J. Optom. Physiol. Opt."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1097\/00006324-199604000-00004","article-title":"Age-Related Changes in the Accommodation Mechanism","volume":"73","author":"Beers","year":"1996","journal-title":"Optom. Vis. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"614","DOI":"10.1167\/iovs.09-3653","article-title":"Age-Related Changes in Accommodative Dynamics from Preschool to Adulthood","volume":"51","author":"Anderson","year":"2010","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"100309","DOI":"10.1016\/j.xops.2023.100309","article-title":"Introducing Dynamic Stimulation Aberrometry: Binocular Objective Accommodation versus Subjective Measures","volume":"3","author":"Hammer","year":"2023","journal-title":"Ophthalmol. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2945","DOI":"10.1016\/j.visres.2003.08.004","article-title":"Amplitude Dependent Accommodative Dynamics in Humans","volume":"43","author":"Kasthurirangan","year":"2003","journal-title":"Vis. Res."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"892","DOI":"10.1080\/00140139.2010.489968","article-title":"Effects of Age on Dynamic Accommodation","volume":"53","author":"Lockhart","year":"2010","journal-title":"Ergonomics"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1507","DOI":"10.1016\/j.visres.2005.11.012","article-title":"Age Related Changes in Accommodative Dynamics in Humans","volume":"46","author":"Kasthurirangan","year":"2006","journal-title":"Vis. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"873","DOI":"10.1097\/OPX.0b013e3181f6f98f","article-title":"Static and Dynamic Accommodation Measured Using the WAM-5500 Autorefractor","volume":"87","author":"Houser","year":"2010","journal-title":"Optom. Vis. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1111\/opo.12964","article-title":"The Use of Autorefractors Using the Image-Size Principle in Determining on-Axis and off-Axis Refraction. Part 3: Theoretical Effect of Pupil Misalignment on Peripheral Refraction for the Grand-Seiko Autorefractor","volume":"42","author":"Atchison","year":"2022","journal-title":"Ophthalmic Physiol. Opt."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Safarian Baloujeh, E., \u00c1vila, F.J., and Gonz\u00e1lez-M\u00e9ijome, J.M. (2024). Effect of Small Angle Misalignments on Ocular Wavefront Zernike Coefficients. Photonics, 11.","DOI":"10.3390\/photonics11090795"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Del \u00c1guila-Carrasco, A.J., Esteve-Taboada, J.J., Papadatou, E., Ferrer-Blasco, T., and Mont\u00e9s-Mic\u00f3, R. (2017). Amplitude, Latency, and Peak Velocity in Accommodation and Disaccommodation Dynamics. BioMed Res. Int.","DOI":"10.1155\/2017\/2735969"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"3282","DOI":"10.1364\/BOE.420334","article-title":"Binocular Dynamics of Accommodation, Convergence, and Pupil Size in Myopes","volume":"12","author":"Ghoushchi","year":"2021","journal-title":"Biomed. Opt. Express"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1046\/j.1475-1313.2002.00070.x","article-title":"Accommodation Dynamics as a Function of Age","volume":"22","author":"Heron","year":"2002","journal-title":"Ophthalmic Physiol. Opt."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2931","DOI":"10.1016\/j.visres.2004.07.005","article-title":"Accommodation Responses to Stimuli in Cone Contrast Space","volume":"44","author":"Rucker","year":"2004","journal-title":"Vis. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"4200","DOI":"10.1364\/BOE.6.004200","article-title":"Dynamics of the near Response under Natural Viewing Conditions with an Open-View Sensor","volume":"6","author":"Chirre","year":"2015","journal-title":"Biomed. Opt. Express"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Safarian Baloujeh, E., and Gonz\u00e1lez-M\u00e9ijome, J.M. (2024). Wavefront Changes during a Sustained Reading Task in Presbyopic Eyes. Sensors, 24.","DOI":"10.3390\/s24123866"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Orduna-Hospital, E., Safarian Baloujeh, E., Navarro, R., and Sanchez-Cano, A. (2023). Optical and Motor Changes Associated with Lighting and near Vision Tasks in Electronic Devices. JEMR, 16.","DOI":"10.16910\/jemr.16.2.3"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.1016\/S0042-6989(97)00336-2","article-title":"Static Aspects of Accommodation: Age and Presbyopia","volume":"38","author":"Mordi","year":"1998","journal-title":"Vis. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1113\/jphysiol.1993.sp019515","article-title":"Inter-Individual Variability in the Dynamics of Natural Accommodation in Humans: Relation to Age and Refractive Errors","volume":"461","author":"Schaeffel","year":"1993","journal-title":"J. Physiol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.exer.2017.12.008","article-title":"Anterior Lens Capsule Strains during Simulated Accommodation in Porcine Eyes","volume":"168","author":"Pellegrino","year":"2018","journal-title":"Exp. Eye Res."},{"key":"ref_30","first-page":"956","article-title":"Massive Increase in the Stiffness of the Human Lens Nucleus with Age: The Basis for Presbyopia?","volume":"10","author":"Heys","year":"2004","journal-title":"Mol. Vis."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1111\/j.1444-0938.2008.00255.x","article-title":"Growth of the Lens: In Vitro Observations","volume":"91","author":"Augusteyn","year":"2008","journal-title":"Clin. Exp. Optom."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1186","DOI":"10.1111\/j.1755-3768.1969.tb02519.x","article-title":"Studies with Impedance Cyclography on Human Ocular Accommodation at Different Ages","volume":"47","author":"Swegmark","year":"1969","journal-title":"Acta Ophthalmol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1113\/jphysiol.1977.sp011938","article-title":"The Force of Contraction of the Human Ciliary Muscle during Accommodation","volume":"270","author":"Fisher","year":"1977","journal-title":"J. Physiol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2235","DOI":"10.1016\/S0042-6989(02)00094-9","article-title":"Numerical Modelling of the Accommodating Lens","volume":"42","author":"Burd","year":"2002","journal-title":"Vis. Res."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2851","DOI":"10.1167\/iovs.15-18413","article-title":"Protein Disulfide Levels and Lens Elasticity Modulation: Applications for Presbyopia","volume":"57","author":"Garner","year":"2016","journal-title":"Investig. Ophthalmol. Vis. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1007\/s10719-020-09961-9","article-title":"Glycation-Mediated Protein Crosslinking and Stiffening in Mouse Lenses Are Inhibited by Carboxitin In Vitro","volume":"38","author":"Nandi","year":"2021","journal-title":"Glycoconj. J."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"04006","DOI":"10.1051\/epjconf\/202226604006","article-title":"Open-View Binocular Double-Pass System for the Study of Dynamic Accommodation","volume":"266","author":"Navarro","year":"2022","journal-title":"EPJ Web Conf."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/14\/4\/1107\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:29:51Z","timestamp":1760027391000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/14\/4\/1107"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,9]]},"references-count":37,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,2]]}},"alternative-id":["jcm14041107"],"URL":"https:\/\/doi.org\/10.3390\/jcm14041107","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,2,9]]}}}